WEDNESDAY, Sept. 19 (HealthDay News) -- West Nile virus infections and deaths continue to climb, federal health officials reported Wednesday, with a new total of 3,142 cases and 134 deaths.

This makes it one of the worst outbreaks of the mosquito-borne disease ever to hit the United States.

While all states except Alaska and Hawaii have reported West Nile virus infections in humans, animals or mosquitoes, two-thirds of the human cases having been reported from seven states -- California, Louisiana, Michigan, Mississippi, Oklahoma, South Dakota and Texas, according to the U.S. Centers for Disease Control and Prevention.

Almost 40 percent of all cases have been reported in Texas.

Of the total number of cases, 1,630 (52 percent) have been classified as neuroinvasive disease (such as meningitis or encephalitis) and 1,512 (48 percent) have been classified as non-neuroinvasive disease, the CDC said.

The 3,142 cases reported so far in 2012 is the highest number of West Nile cases reported to the CDC through the third week of September since 2003.

The best way to avoid the virus is to wear insect repellant and support local programs to eradicate mosquitoes. There is currently no treatment for West Nile virus and no vaccine to prevent it, according to the CDC.

Typically, 80 percent of people infected with the virus develop no or few symptoms, while 20 percent develop mild symptoms such as headache, joint pain, fever, skin rash and swollen lymph glands, according to the CDC.

Although most people with mild cases of West Nile virus will recover on their own, the CDC recommends that anyone who develops symptoms see their doctor right away.

People older than 50 and those with certain medical conditions, such as cancer, diabetes, hypertension, kidney disease and organ transplants, are at greater risk for serious illness.

The best way to protect yourself from West Nile virus is to avoid getting bitten by mosquitoes, which can pick up the disease from infected birds.

The CDC recommends the following steps to protect yourself:

Use insect repellents when outside.

Wear long sleeves and pants from dawn to dusk.

Don't leave standing water outside in open containers, such as flowerpots, buckets and kiddie pools.